Recently a demand for forming characters with higher quality and printing or displaying them with the use of a character forming apparatus has been growing, and such a character forming apparatus has been required to have an outline font with which character output with high quality can be realized, instead of the conventional bit map font.
Such outline font is stored in a font ROM in a system, as font data having a plurality of coordinates obtained by sampling outlines of characters. The coordinates are read out as the need arises, and the coordinates are changed in accordance with the size and style of the character. Then, by painting over the inside of the outline, a character pattern is formed. In comparison with the conventional character formation with the use of the bit map font, this method has advantages such as a higher degree of freedom of character patterns, with which characters of high quality can be formed even in the case where various sizes of characters are formed. However, since coordinates of control points increase, the data quantity of the font data drastically expands. Besides, a longer period of time is required for conversion to bit map, thereby leading to a problem that the processing speed lowers.
Incidentally, the character pattern is formed by combining various stroke patterns, and likewise a Chinese character is formed by combining various radicals. Therefore, by restoring previously stored specific radical patterns so that a character thus formed is well-balanced, and by synthesizing data on the radical patterns as font data, it is possible to reduce types of stroke patterns and to form characters at a high speed.
However, in order to form one character pattern, it is necessary to combine several basic patterns so as to form each radical pattern. In this case, radical patterns having simple shapes tend to cause a character formed to be badly balanced, thereby resulting in that the character formed by combining the radicals has lower quality. In the case where there are many basic patterns, this causes not only the data capacity to expand, but also the period of time required for extracting basic patterns and synthesizing font data to increase.
Furthermore, in the character pattern forming method by referring to codes of figure elements constituting the character, applying an enlarging or reducing operation to data of the figure elements in accordance with the character size, and synthesizing the data, such method is suitable for forming character patterns, but it is not designed so as to cope with minute changes such as changes with respect to each stroke. As a result, in forming a certain radical pattern, a pattern having the same shape is always restored as an element pattern, and subtle differences in the radical included in the characters cannot appear.